This comparison will look at four available replacement 152mm ML-20S barrels for the SU-152/ISU-152 SPG to see how they stack up, but a couple have been around for quite a few years now and this shows in the final analysis in terms of accuracy.
It should be noted the ISU-152 (in Russian ИСУ-152) is incorrectly referred to as the JSU-152 in the West. This is due to ‘Iosef Stalin’ being pronounced Joseph Stalin in English, but there is no J in the Cyrillic alphabet, hence the correct translation should be ISU-152.
The five sets included here are from ABER (set #35 L-40), armorscale (set #B35-085), ARMO (set #35732), CMK/Hot Barrels (set #HB026) and RB Model (set #35B63) with two of the sets, the armorscale and CMK/Hot Barrels also including additional resin parts for the gun mantlets/mountings.
The ABER barrel set (#35 L-40) just has the aluminium barrel and a machined brass muzzle brake with the metal barrel having the correct taper and step segments and also features fine rifling inside the hollowed out muzzle. The machined brass muzzle brake has the correct 12 gas slots fully opened out without any cleanup required.
This barrel is optomized to use with the Eastern Express KV-14 (SU-152) (kit #35103) but a little work is required to fit and it could also be used on the Dragon 39-45/Korean War series ISU-152 kits (kit #6047, 6803) with kit modifcations due to the undersized Dragon kit barrel and mantlet locating hole.
It can also be used on the newer Tamiya ISU-152 SPG (kit #35303) with only minor modifications (see full barrel review).


armorscale set (#B35-085) sees the barrel similar to the ABER barrel in having the aluminium barrel and a machined brass muzzle brake with the metal barrel having the correct taper and step segments and also features fine rifling inside the hollowed out muzzle. The machined brass muzzle brake has the correct 12 gas slots fully opened out without any cleanup required with the small differences between this and the ABER barrel being the length of the large locating stub, the thickness of the barrel muzzle and the length of the slots in the muzzle brake which are slightly longer in the armorscale part which better match photos of the actual muzzle brake.
Also included are four resin and five etched parts for the complete gun mantlet/mounting to include additional detail and to ensure the parts will fit to the target kits overcoming any dimensional issues with the kit parts.
This set is designed primarily for the older Dragon 39-45/Korean War series ISU-152 kits but could be used on the Eastern Express kit with minor kit modificationsor on the newer Tamiya ISU-152 SPG (kit #35303) with only minor modifications (see full barrel review).
But note, while the barrel can be used on the Eastern Express kit the mantlet cannot as there were different features between the SU and ISU vehicles.









This RB Model set #35B63 consists of the aluminium barrel a machined brass muzzle brake and is basically identical to the armorscale 152mm ML-20S Barrel for Soviet ISU-152, set #B35085 apart for the longer neck pin and no etched or resin parts.
This set is designed primarily for the older Dragon 39-45/Korean War series ISU-152 kits but could be used on the Eastern Express kit with minor kit modifications or on the newer Tamiya ISU-152 SPG (kit #35303) with only minor modifications (see full barrel review).
But note, while the barrel can be used on the Eastern Express kit the mantlet cannot as there were different features between the SU and ISU vehicles.

The overall length and diameter of the ABER barrel/muzzle brake matches exactly to a set of 1:35 plans in the 7/1988 edition of Panzer Magazine as well as to enlarged 1:72 plans in the 4/2001 issue of Tank Master Magazine.
The two small locking screws are not included and could be added for additional detail.
As mentioned the armorscale barrel is very similar to the ABER barrel with the overall length and diameter barrel/muzzle brake also matching exactly to same plans as above. The sizes of the mantlet and gun mountings also match these plans well within acceptable tolerances. The muzzle brake slots are better sized but the two small locking screws are not included and could be added for additional detail.
The ARMO barrel is about 1.5mm too short while the correct diameter although the taper is a little exaggerated. The biggest problem with this barrel is the muzzle brake gas slots are not fully opened out but are simply cross cuts leaving only the centre third of the slot actually open. The two small locking screws are not included and could be added for additional detail.
The CMK/Hot Barrels is almost 3mm too short and also 1.5mm too narrow in diameter at the breech end with the gas slots in the resin muzzle brake not fully formed on my example leaving quite a bit of work to fully open these out. On the resin mantlet the cast texturing is quite subtle but three of the large bolt heads has substantial air bubbles in them and would need to be filled or replaced.
The two small locking screws are not included and could be added for additional detail.
This set is basically identical to the armorscale 152mm ISU-152, set #B35085 apart for the longer neck pin and no etched or resin parts with the comments on the armorscale barrel also applying here.
only the ABER, armorscale and RB Model barrels are the correct dimensions

Comparisons of the muzzle brakes and barrel rifling
with the ABER, armorscale and RB Model barrels





Images of the real muzzle brakes for comparison, note the retaining screws missing from all barrels

Images courtesy Saul Garcia ©
As mentioned the barrels/muzzle brakes in the ABER, armorscale and RB Model sets are similar with both being accurate in length and diameter although the armorscale and RB Models muzzle brake slots are slightly better sized.
If you want just the barrel on it's own then the ABER or RB Model would be a good option, keeping in mind that the ABER set is optimised for the Eastern Express kit and some work is needed to fit either to the Dragon kits.
If you want an accurate barrel as well as more in the way of better detailed mantlet and gun mounting then the armorscale set would be the choice and while designed for the Dragon kits can be fitted to others with only a little work.
The remaining two options (ARMO and CMK/Hot Barrels) are not really worth considering in light of the availability of the ABER, armorscale and RB Model sets as they have dimensional as well as detail issues to contend with.
But on a pure accuracy and detail aspect for the barrel itself the points would have to go to the armorscale/RB Model barrel sets.
Note, all barrel muzzle brakes lack the two small locking screws which can be easily added.